1. Field of the Invention
The present invention relates to an ink-jet head in which an ink passage has a filter therein.
2. Description of Related Art
An ink-jet recording apparatus that ejects ink to form an image comprises an ink-jet head having many nozzles for ejecting ink and also having therein ink passages that lead to the nozzles. The ink-jet head, having an ink receiving port for receiving ink from an ink tank, is connected to the ink tank via a tube, etc., so that ink may be supplied from the ink tank through the ink receiving port into the head.
In such a tube-connection type head, in general, a joint member is disposed between the ink receiving port and the tube. In a known technique, for example, a joint member has two conical members confronting each other on their open bottoms to define therein two funnel shaped spaces, and a filter for removing dust contained in ink is disposed between the two funnel shaped spaces (see U.S. Patent Application Publication No. 2002-196318).
In this technique, an ink passage formed by the two funnel shaped spaces becomes relatively larger at its portion around the filter. With this configuration, flow velocity and pressure of ink fall around the filter, to often generate bubbles resulting from air contained in ink. The bubbles may hinder ink flow through the filter, enter an ink passage of the head to deteriorate election performance, and, in the worst case, cause failure of ink ejection.